Expansible linkage having connectors with integral pretensioning means



ug. 6, 1963 K. WOLFINGER 3,099,908

EXPANSIBLE LINKAGE HAVING CONNECTORS WITH INTEGRAL PRETENSIONING MEANS 2 Sheets-Sheet 1 Filed March 17, 1961 '9.7 mvENToR Kurt Wolfng er ATTORNEY ug- 5, 1963 K. WOLFINGER 3,099,908

EXPANSIBLE LINKAGE HAVING CONNECTORS WITH INTEGRAL PRETENSIONING MEANS 2 Sheets-Sheet 2 Filed March 1'7, 1961 K :Nw-:mon Kurt Wolfnger.

ATTORNEY United States Patent 3,099 908 EXPANSIBLE LINKAGE HAVING CONNECTRS WITH INTEGRAL PRETENSIONING MEANS K11 Whser, Setmana, Kries Calw, Germany, assigner to Rodi & Wienenberger Aktiengesellschaft, Pforzheim, Germany A Filed Mar. 1,7, 1961, Ser. No. 96,516 Claims priority, application Germany Mar. 19, 1960 7 v12 Claims. (Cl.`59f-'79) The present invention relates generally to 'bands and more particularly to an expansible bracelet, especially for wrist watches.

The band is constructed of hollow links and intermediate or connecting links flexibly and expansibly connecting the hollow links together. These intermediate links are pivotally mounted against spring action. The hollow links are sleeves disposed in two layers and staggered with respect to one another in the longitudinal direction of the bracelet. The staggered upper and lower sleeves may be of either single or `double link type. 'Ihe connecting links comprise U-'shapedclips disposed in the longitudinal openings of the links. They each have one leg inserted in the open end of a sleeve of one layer andthe other leg inserted in an adjacent staggered sleeve of the other layer. A leaf spring is disposed in each sleeve of at least one layer and opposes pivoting of the connecting clips and detains the latter in the sleeve.

The band or bracelet according to the present invention differs from lconventional bands due to a novel construction of the U-shaped connecting clips and their as# sembly with new leaf springs, and connection with the sleeves.

According to the invention, lat :least one of the legs of the U-svhaped clips'is disposed in an open end of the sleeves, and is split longitudinally to form two arms. One arm is disposed under and the other over the leaf springs which are disposed within the sleeves. The arms have an initial stress when engaging the leaf springs. rThe other leg of the U-shaped clip may engage and accommod ate a terminal ange of the longitudinal wall of the sleeves by a recess provided near the bight portion of the clip. Alternatively this leg may engage a recess in the leaf spring by Emeans of an inflection acting as a stop. I n one embodiment of the bracelet there are separate upper and lower links and the leaf springs, acting together with the split ar-ms of the U-shaped clips, have a cross section forming an obtuse angle. In another embodiment of the bracelet the upper and lower links are united to form a double link, and the leaf springs are plane yand lie along a diagonal common to the united sleeves.

Additional objects and advantages of the present invention -will become apparent upon consideration of the following description when taken in conjunction with the accompanying drawings in which:

FIGS. l to 7 illustrate one embodiment, namely- FIfG. l is a side view of one embodiment of the band illustrated in the' contracted state on the left side in elevation and on the right in `section taken substantially along the plane defined by line 1 1 of FIG. 2;

Y FIG. v2y is a horizontal sectional` view taken substantially along the plane deiinel by line 2-2 of FIG. 1;

FIG. 3 is a side combined section-elevation similar to FIG. 1, but illustrating the bracelet in the expanded state;

FIG. 4 is a sectional view taken substantially along a portion of the plane defined by line 4-4 of FIG. 3, but illustrating only the structure disposed in this plane, except `for the edge wall of the links antiV arm 11" which isfshown to indicate its relationship ram 11" and spring 15;

ice

FIG. 5 is a fragmentary perspective of the terminal part of a link sleeve;

FIG. 6l is a perspective view of the connecting clip;

FIG. 7 is a perspective view of the leaf spring;

FIGS. 8 to 14 illustrate a second embodiment, namely:

FIG. 8 is a side combined elevation-section similar to FIG'l but of another embodiment illustrated in the contracted state with the right side taken substantially along the plane defined by line 8-8 4of FIG. 9; FIG9Vis a horizontal section view taken substantially along the plane .desired by aine f9 of FIG. s;

FIG.v l0 is a combined elevation-section illustrating the band in the expanded state; FIG. 1l is a sectional view taken substantially along the plane defined by line 11-11 of FIG. 10; `FIG. l2 isa perspective view of the connecting slip of the second embodiment;

' FIG. 13 is a planof one for-m of the leaf spring for the second embodiment, and

` FIG. 14 is a plan of another form of the leaf spring for the second embodiment.

The irst embodiment (FIGS. l to 7) of the expansible bracelet has two separate superposed layers or rows 1, 2 of links 3, 4 in the form of sleeves having a rectangular cross section. The links are staggered with respect to one another in the longitudinal direction of the band. From the longitudinal walls' 5 of the lower layer 2 of the links 4, short terminal flanges 6 are bent to -face inwardly'toward each other at right angles to be disposed in openings 7 (FIG. 5). lThe connecting links are U-shaped clips 8 (-FIG. 6) of spring material having a rectangular cross section. Each clip is formed'from Ia single strip of material and includes a 'bight portion 9, a leg 10 bent at right angles with the bight portion, and another leg includingtwo" arms .11 and 11, each about -half as wide as leg 10 Iand bent at right angles from the other end of the bight portion 9. To for-m the arms, the portion of the strip used to form them and an adjacent part of the bight portion are split by a longitudinal slit 12.' The yarms 11 and 11 are bent olf at bight portion 9, at different distances yfrom leg 10. The difference between these distances corresponds to the thickness of the ymetal sheet of leaf spring 15. In addition. the two arms 11 -and 11 are prestressed, bent somewhat towards one another, and provi-ded at their ends with bevels 13 extending from the outside to the inside. On the same side of the clip 8' where higher arm 11 is disposed land underlying sa-me, leg 1li has a rectangular recess 14 adjacent bight portion 9. The third part of this embodiment of the bracelet is the leaf spring 15 bent so that its legs Vform yan obtuse 'angle in cross section (FIG. 7).

Before bending the flanges 6 into opening 7, the leaf springs 15 are inserted into the links 3 of the upper layer 1. The connecting clips 8 are inserted with leg 1) and the two anns '11', 11" through the openings 7 of the links 3 and 4 of the two layers 1 -and 2 in such a way that the lower arm 11" engages the leaf spring 15 on its lower surface, while the other yarm 11 engages its upper surface. 'he insertion of the leaf spring 15 between the arms 11', 11 .against their spring action is facilitated by the terminal bevels 13. This causes an initial stress of the arms 1v1', 11, brought about by their `mutual bending, and the cooperation of the leaf spring 15. Thus, the clip 8 is biased in -the direction toward that side of the clip which has the higher arm 11. The clip 8 is pivoted While in engagement with the flange 6 of the longitudinal wall of the lower links 4 by the recess 14. in its leg lil and is detained'in the links Sand 4,. The links 3 of the upper layer 1 'and the links 4 ofthe lower layer 2 are pivotally connected to the connecting clips 8V and thus may move toward 'one another in the longitudinal direction of the band, thereby contracting the bracelet, and can be expanded against the action of the arms 11', 11" and leaf spring 15 biasing the links toward each other.

The second embodiment (FIGS. 8 to 14) of the bracelet is constructed `of `double links |16 consisting of two sleeves 16', 16" of substantially square cross section and ofset with respect to one another. The sleeves 16 form the upper layer '17 and sleeves 16 for-m rthe lower layer 18 of the bracelet, the sleeves of which are offset from.I those of layer 17. The double 1in-ks l16 are formed by bending a rectangular metal sheet. A central bending point 19 of the ,sheet lies at the connecting point of the double links, while fthe terminal edges 20, 21 of the sheet Ifreely oppose the bending point 19. The flanges 22, 23 of the double links 16 which are the ends of fthe rectangular metal sheet, lie adjacent bending point 19 and may be diposed obliquely to the longitudinal direction of the band. The connecting links of the second embodiment are also U-shaped clips 3 (FIG. 12) with a bight portion 9, -leg 10 and two arms 11', -1-1, offset in height and bent towards one another, and terminal bevels 13. The leg 10 has an inflection 24 forming an angled portion thereon. In this embodiment, plane leaf springs 25 or 25" (FIGS. 13 and 14), rectangular in outline, are used, lwhose width substantially corresponds to the comcm-on diagonal running through the two sleeves 16 and 16 of the double link 16. These springs have rectangular recesses 26, in fthe same longitudinal side in spring 25 (FIG. '13) and in opposite Ilongitudinal sides in spring 25 (FIG. 14), 'and two bores 27 in their center for achieving a smooth spring action.

The leaf springs 25 are inserted longitudinally into the double links 16 in alignment with the diagonal of the link sleeves 16', 16 so that their recesses 26 are in the lower sleeves 16". Ihe connecting clips 8" are inserted with their leg 10 land arms 11', 11" extending through the side openings of the double link 16. The upper half `of the Ileaf spring 2-5' is gripped by the two arms 11, 11" along its top and bottom surfaces, respectively. Due to the initial stress of these two arms and their cooperation with the leaf spring 25', the clips 8" are biased in the direction toward lthat side of the clip which has the higher -arm 11. The clip 8" is brought linto engagement with the recess 26 of the leaf spring 25' by its deflection 24 forming the angled pontion when Ibeing inserted into the lower sleeve 16 of the link, and is pushed into engagement therewith and secures the connection of the three band components, double link 16, connecting clip v8, and leaf spring 25. The double links 16 are contracted in :the longitudinal direction of the band, thereby shortening the bracelet. Yet the bracelet may be expanded against the action of the arms 11', 11" and leaf spring 25', the `double links 16 thereby moving away from one another, which is facilitated, as is their gliding into one another, by the oblique center flanges 22, 23'. 'If the leaf springs 25" (FIG. 13) with recesses on .the opposite longitudinal side are used, the connecting clips 8 are accordingly arranged at the two edge sides of the bracelet inversely regarding their leg 10 and 'their arms 11', 11".

It will be runderstood that the above description of the present invention is susceptible to various modifications, changes, and adaptations, and the same are intended Ito be comprehended within the meaning and range of equivalents of the .appended claims.

I claim:

1. An expansion band, comprising, in combination: a plurality of body links arranged to form two ylayers of sleeves, 4said links being staggered with respect to each other; a plurality of leaf springs disposed one in each of the sleeves of .at least one layer; and a plurality of connecting links in the form of U-shaped clips, said connecting links connecting each said body link -to a respective next adjacent body link, each said connecting link having one leg vdisposed in a sleeve of one layer in one body link Vand the other leg disposed in an adjacent sleeve of the other layer in an adjacent body link, each of said leaf springs having generally oppositely yfacing surfaces, a portion of one of said surfaces bearing against its associated body link, said clips each having one leg split longitudinally to yform arms disposed one against each of said rsurfaces of i-ts associated leaf spring, the one of said arms the closest to said surface portion bearing against the other said surface of its associated leaf spring, said arms having an initial stress directed against the leaf spring, `whereby the links are biased toward each other.

2. The expansion ban-d of claim 1, wherein said arms are connected to the bight portion of the clip at positions spaced apart a distance corresponding to .the thickness of the leaf spring, the -arrns being bent -toward each other to achieve ltheir initial stress.

3. The expansion band of claim 1, wherein the ends of said arms are beveled inwardly, whereby when pushed onto the leaf spring said amis are guided one to each side.

4. The expansion band of claim 1, wherein the body links are independent of each other, and each lleaf spring has Itwo legs at an obtuse angle in cross section, one of said clips being connected .to each leg of each leaf spring.

5. The expansion band of claim 1, wherein said body links are open ended sleeves and those in one layer have terminal portions of their longitudinal walls bent into the sleeve lopenings, the :other arm off each clip having la recess at its edge opposing the longitudinal wall of the sleeve near the bight portion of the clip for accommodating said terminal portions.

l6. The expansion band of claim 1, wherein the body links are double sleeves including 'one fnom the upper layer and one from the lower layer, each leaf spring being planar.

7. The expansion band of claim 1, wherein each leaf spring has a recess, and the other leg of each connecting link is provided with lan inclined portion and an :offset portion which iit into said recess.

8. An expansion bracelet, comprising, in combination: a plurality of main links deinlng sleeves disposed in two rows, said links being staggered with respect to each other; connecting links each pivotally connected to a main link sleeve of each row; leaf springs for the connecting links, one leaf spring being Idisposed in each sleeve of at least lone row, each connecting link being generally U-shaped and having one leg pivotally connected to the sleeve fof a main link in one row and another leg pivotally connected to the sleeve yof another main link in another row, Ione leg of each connecting link being resilient and split 4by :a longitudinal slit thereby to form two arms which are ioifset from each other in one direction transversely of said slit, said arms when unstressed being spaced apart for at least a portion of their lengths in another direction transversely of said slit a distance less than the thickness of the leaf spring, said arms resiliently engaging said leaf spring one on each side, said arms extending over said sides and thereby being stressed and biasing the connecting links and thus the sleeves toward each other, and means on the other leg of each connecting link pivotallly cooperable with the sleeve 0f one of said main links whereby the bracelet may be expanded against the spring action `of the stressed arms and the leaf spring, said bracelet including means for maintaining said connecting links in their assembled positions.

9. rIlhe expansion bracelet of claim 8, wherein said arms are connected to the bight portion of each connecting link at different distances from said Iother leg and lare bent toward each other and stressed when engaging said leaf spring. l'

10. The expansion bracelet of claim 8, wherein s aid means includes an angled portion on said other [leg diS- posed in a recess in another of said leaf springs.

aoeaeos 1l. The expansion bracelet of claim 8, wherein said means includes a notch in said other leg accommodating a ange `on the cooperating sleeves.

12. In an expansion band including hollow links, intermediate links flexibly and expansibly connecting the hollow llinks together, the hollow links defining sleeves disposed in two layers, the hollow links being staggered with respect to each other, the intermediate links being U-shaped clips ihaving one leg disposed in a sleeve oone `layer and the other leg disposed in an adjacent sleeve of the other layer, a plurality ott leaf spring means disposed one in each of the sleeves of `one layer for biasing the hollow links toward each other, and the band including means for maintaining said connecting links in their `assembled positions, the improvement that: said clips each has one leg which is resilient tand split fby a longitudinal slit to form two arms which rare oiset from each other in one direction traversely of said slit, said arms 6 when unstressed being spaced apart for at least a portion of their lengths in 'another direction transversely of said slit a distance less than the thickness of the leaf spring means, and said arms are disposed one on each side of each lleaf spring means and t-hus :have 'an initial stress directed against each leaf spring means.

References Cited in the tile of this patent UNITED STATES PATENTS 2,689,450 Stiegele Sept. 21, 1954 2,918,785 Bartholoma et al. Dec. 29, 1959 2,957,303 Sasaki Oct. 25, 1960 FOREIGN PATENTS 932,867 Germany Sept. 12, 1955 830,207 Great Britain Mar. 9, 1960 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N0. 3,099,908 August 6, 1963 Kur-t Wolfnger It is hereby certified that errer appears in Jthe above numbered petent requiring correction and that the said Letters Patent should read as corres ted below In the grant, line 1, and in the heading to the printed specification, line 4, for "Kr-ies Calw", each occurrence, read Kreis Calw Signed and Sealed this 21st day of January 1964.

SEAL) f [test:

ERNEST W. SWIDER EDWIN L. REYNOLDS Attesting Officer AC ting Commissioner of Patents 

1. AN EXPANSION BAND, COMPRISING, IN COMBINATION: A PLURALITY OF BODY LINKS ARRANGED TO FORM TWO LAYERS OF SLEEVES, SAID LINKS BEING STAGGERED WITH RESPECT TO EACH OTHER; A PLURALITY OF LEAF SPRINGS DISPOSED ONE IN EACH OF THE SLEEVES OF AT LEAST ONE LAYER; AND A PLURALITY OF CONNECTING LINKS IN THE FORM OF U-SHAPED CLIPS, SAID CONNECTING LINKS CONNECTING EACH SAID BODY LINK TO A RESPECTIVE NEXT ADJACENT BODY LINK, EACH SAID CONNECTING LINK HAVING ONE LEG DISPOSED IN A SLEEVE OF ONE LAYER IN ONE BODY LINK AND THE OTHER LEG DISPOSED IN AN ADJACENT SLEEVE OF THE OTHER LAYER IN AN ADJACENT BODY LINK, EACH OF SAID LEAF SPRINGS HAVING GENERALLY OPPOSITELY FACING SURFACES, A PORTION OF ONE OF SAID SURFACES BEARING AGAINST ITS ASSOCIATED BODY LINK, SAID CLIPS EACH HAVING ONE LEG SPLIT LONGITUDINALLY TO FORM ARMS DISPOSED ONE AGAINST EACH OF SAID SURFACES OF ITS ASSOCIATED LEAF SPRING, THE ONE OF SAID ARMS THE CLOSEST TO SAID SURFACE PORTION BEARING AGAINST THE OTHER SAID SURFACE OF ITS ASSOCIATED LEAF SPRING, SAID ARMS HAVING AN INITIAL STRESS DIRECTED AGAINST THE LEAF SPRING, WHEREBY THE LINKS ARE BIASED TOWARD EACH OTHER. 